## C=C=O (*see note)

 C3 = C1 = O2
Tell me about the atomic charges, dipole moment, bond lengths, angles, bond orders,
molecular orbital energies, or total energy.
Tell me about the best Lewis structure.

## Atomic Charges and Dipole Moment

C1 charge= 0.706
O2 charge=-0.297
C3 charge=-0.409
with a dipole moment of 1.12389 Debye

## Bond Lengths:

between C1 and O2: distance=1.190 ang___ between C1 and C3: distance=1.371 ang___
between O2 and C3: distance=2.561 ang___

## Bond Angles:

for C3-C1-O2: angle=179.9 deg___

## Bond Orders (Mulliken):

between C1 and O2: order=1.787___ between C1 and C3: order=1.528___
between O2 and C3: order=0.071___

## Best Lewis Structure

The Lewis structure that is closest to your structure is determined. The hybridization of the atoms in this idealized Lewis structure is given in the table below. Please note that your structure can't be well described by a single Lewis structure, because of extensive delocalization.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for C1-O2 with 1.9993 electrons
__has 35.16% C 1 character in a sp1.38 hybrid
__has 64.84% O 2 character in a sp1.53 hybrid

2. A bonding orbital for C1-O2 with 1.9786 electrons
__has 32.01% C 1 character in a p-pi orbital ( 99.60% p 0.40% d)
__has 67.99% O 2 character in a p-pi orbital ( 99.76% p 0.24% d)

3. A bonding orbital for C1-C3 with 1.9985 electrons
__has 60.69% C 1 character in a sp0.72 hybrid
__has 39.31% C 3 character in a s0.87 p3 hybrid

4. A bonding orbital for C1-C3 with 1.9933 electrons
__has 43.18% C 1 character in a p-pi orbital ( 99.60% p 0.40% d)
__has 56.82% C 3 character in a p-pi orbital ( 99.54% p 0.46% d)

8. A lone pair orbital for O2 with 1.9790 electrons

9. A lone pair orbital for O2 with 1.8031 electrons
__made from a p-pi orbital ( 99.85% p 0.15% d)

10. A lone pair orbital for C3 with 1.9744 electrons

72. A antibonding orbital for C1-C3 with 0.1849 electrons
__has 56.82% C 1 character in a p-pi orbital ( 99.60% p 0.40% d)
__has 43.18% C 3 character in a p-pi orbital ( 99.54% p 0.46% d)

-With core pairs on: C 1 O 2 C 3 -

#### Donor Acceptor Interactions in the Best Lewis Structure

The localized orbitals in your best Lewis structure can interact strongly. A filled bonding or lone pair orbital can act as a donor and an empty or filled bonding, antibonding, or lone pair orbital can act as an acceptor. These interactions can strengthen and weaken bonds. For example, a lone pair donor->antibonding acceptor orbital interaction will weaken the bond associated with the antibonding orbital. Conversly, an interaction with a bonding pair as the acceptor will strengthen the bond. Strong electron delocalization in your best Lewis structure will also show up as donor-acceptor interactions.
Interactions greater than 20 kJ/mol for bonding and lone pair orbitals are listed below.

The interaction of the second bonding donor orbital, 2, for C1-O2 with the second lone pair acceptor orbital, 11, for C3 is 43.2 kJ/mol.

The interaction of lone pair donor orbital, 8, for O2 with the antibonding acceptor orbital, 71, for C1-C3 is 47.5 kJ/mol.

The interaction of the second lone pair donor orbital, 9, for O2 with the second antibonding acceptor orbital, 72, for C1-C3 is 425. kJ/mol.

The interaction of lone pair donor orbital, 10, for C3 with the antibonding acceptor orbital, 69, for C1-O2 is 84.3 kJ/mol.

## Molecular Orbital Energies

The orbital energies are given in eV, where 1 eV=96.49 kJ/mol. Orbitals with very low energy are core 1s orbitals. More antibonding orbitals than you might expect are sometimes listed, because d orbitals are always included for heavy atoms and p orbitals are included for H atoms. Up spins are shown with a ^ and down spins are shown as v.

14 ----- 1.419

13 ----- -0.555

12 ----- -1.122

11 ----- -7.280

10 -^-v- -6.618

9 -^-v- -8.138

8 -^-v- -11.98

7 -^-v- -12.55

6 -^-v- -13.86

5 -^-v- -19.55

4 -^-v- -28.99

3 -^-v- -269.4

2 -^-v- -270.4

1 -^-v- -509.9

## Total Electronic Energy

The total electronic energy is a very large number, so by convention the units are given in atomic units, that is Hartrees (H). One Hartree is 2625.5 kJ/mol. The energy reference is for totally dissociated atoms. In other words, the reference state is a gas consisting of nuclei and electrons all at infinite distance from each other. The electronic energy includes all electric interactions and the kinetic energy of the electrons. This energy does not include translation, rotation, or vibration of the the molecule.

Total electronic energy = -151.2725856556 Hartrees

*Note: The CCO triplet state is lower in energy.